Network construction type virtual synchronous machine control method based on lead-lag correction

Abstract

The invention discloses a network construction type virtual synchronous machine control method based on lead-lag correction, and the method comprises the steps: replacing an output phase angle generation link of the network construction type virtual synchronous machine control method with an output phase angle generation link based on lead-lag correction, and adjusting the lead correction parameter and the lag correction parameter which are additionally introduced. The problems of dynamic oscillation and overshoot of the grid-connected active power and the output frequency of the grid-forming type virtual synchronous machine under the disturbance of an active power reference instruction, a power grid frequency and the like can be effectively solved; compared with a network construction type virtual synchronous machine, the method has the advantages of capability of eliminating grid-connected active steady-state deviation, more control freedom degrees, higher grid-connected active response speed, smaller output frequency response overshoot amplitude and smaller output frequency change rate, and can be applied to the field of grid-connected control of the network construction type virtual synchronous machine in the power electronic technology.

Description

Technical Field

[0001] This invention relates to the field of grid-type virtual synchronous machine control technology, and in particular to a grid-type virtual synchronous machine control method based on lead-lag correction. It is applicable to the field of grid-connected control of grid-type virtual synchronous machines in power electronics technology, as well as the field of microgrid integration into distribution networks that include such grid-type virtual synchronous machines. Background Technology

[0002] The Grid Forming Virtual Synchronous Generator (GFVSG) incorporates the rotor motion equations and primary voltage regulation control equations of traditional synchronous machines into the control structure of power electronic converters, enhancing the power electronic converter's ability to autonomously construct voltage and frequency. GFVSG grid-connected systems can optimize the dynamic response performance of grid-connected active power and output frequency by adjusting virtual inertia parameters, virtual damping parameters, and loop reconfiguration. This allows them to suppress dynamic oscillations in grid-connected active power and output frequency under disturbances such as active power reference command steps and grid frequency steps. However, the ability of GFVSGs to suppress dynamic oscillations and overshoot in grid-connected active power and output frequency still needs further improvement.

[0003] To this end, various studies have been conducted, such as the article entitled "A dual-adaptivity inertia control strategy for virtual synchronous generator", LI MY, HUANG WT, TAI NL, et al, IEEE Transactions on Power Systems, 2020, 35(1), 594-604 ("A dual-adaptive virtual inertia control strategy for virtual synchronous generator", IEEE Power Systems Proceedings, 2020, Vol. 35, No. 1, pp. 594-604). This article proposes a dual-adaptive virtual inertia parameter control method, which suppresses the dynamic oscillation and overshoot of the grid-connected active power and output frequency of the virtual synchronous generator under step disturbances such as active power reference command and grid frequency by adaptively adjusting the virtual inertia parameter. However, there are problems with the nonlinear change of virtual inertia parameter and the difficulty in determining the adaptive adjustment range of parameter.

[0004] The article, titled “A reference-feedforward-based damping method for virtual synchronous generator control”, YU Y, SANJAY KC, GIBRAN DA, et al, IEEE Transactions on Power Electronics, 2022, 37(7), 7566-7571 (“Virtual Synchronous Generator Damping Control Method Based on Active Power Reference Command Feedforward”, IEEE Power Systems Proceedings, Vol. 37, No. 7, 2022, pp. 7566-7571), proposes a virtual synchronous generator damping control method based on active power reference command feedforward compensation. This method can effectively suppress the dynamic oscillation and overshoot of the grid-connected active power and output frequency of the virtual synchronous generator under the active power reference command step disturbance while keeping the virtual inertia parameter unchanged. However, it has the limitation of insufficient adaptability to the grid frequency step disturbance condition.

[0005] The article, titled "Active Power Oscillation Suppression Strategy Based on Active Power Feedforward Compensation," published in *Power System Protection and Control*, Vol. 51, No. 14, 2023, pp. 118-126, proposes a method for suppressing dynamic active power oscillations in grid-connected GFVSGs based on active power feedforward compensation. This method can effectively suppress the dynamic oscillations and overshoot of GFVSG grid-connected active power and output frequency under two disturbances: active power reference command step and grid frequency step. However, it has the disadvantages of limited increase in control degrees of freedom and weakened ability to suppress mid-to-high frequency harmonic component disturbances.

[0006] The article, titled "An Active Oscillation Damping Strategy for Grid-Connected VSG Based on Energy Reconfiguration," published in the *Acta Energiae Solaris Sinica*, Vol. 46, No. 1, 2025, pp. 300-308, proposes an energy-reconfigurable method for suppressing active oscillations in grid-connected GFVSGs. This method effectively suppresses dynamic oscillations and overshoot of the active power and output frequency of GFVSGs under step disturbances such as active power reference commands and grid frequency by reconfiguring the energy storage, injection, and consumption of the GFVSG grid-connected system. It also has the advantage of having many degrees of control freedom, but it suffers from disadvantages such as high system control order, complex parameter design, and difficulty in digital implementation.

[0007] As can be seen from the above, although the existing technology can suppress the dynamic oscillation and overshoot of the active power and output frequency of the GFVSG grid connection to a certain extent under different disturbances such as active power reference command and grid frequency, it still has the disadvantages of nonlinear parameter changes, insufficient adaptability, limited control freedom, complex parameter design, and the ability to suppress the dynamic oscillation and overshoot of the active power and output frequency of the GFVSG grid connection under step disturbances such as active power reference command and grid frequency still needs to be further improved. Summary of the Invention

[0008] To overcome the limitations of existing technical solutions described in the background section, this invention addresses the technical bottleneck of dynamic oscillations and overshoot in the grid-connected active power and output frequency of grid-connected virtual synchronous machines. It provides a control method for grid-connected virtual synchronous machines based on lead-lag correction. This control method effectively suppresses the dynamic oscillations and overshoot in the grid-connected active power and output frequency of the grid-connected virtual synchronous machine. It effectively solves the problem of dynamic oscillations and overshoot in the grid-connected active power and output frequency under disturbances such as active power reference commands and grid frequency. Compared to grid-connected virtual synchronous machines, it has advantages such as eliminating grid-connected active power steady-state deviation, more control degrees of freedom, faster grid-connected active power response speed, smaller output frequency response overshoot amplitude, and smaller output frequency change rate.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A control method for a network-type virtual synchronous machine based on lead-lag compensation includes the following steps:

[0011] Step 1, power calculation section: First, collect the grid-connected current i of the grid-connected virtual synchronous machine. a i b i c and output voltage u a u b u c The dq component I of the grid-connected current oriented by the output phase angle θ of the network-type virtual synchronous machine is obtained through single synchronous rotating coordinate transformation. d I q and the dq component of the output voltage U d U q Then, the grid-connected active power P of the grid-type virtual synchronous machine is obtained through the power calculation equation. e And grid-connected reactive power Q e ;

[0012] Step 2, primary voltage regulation section, based on the grid-connected reactive power Q of the network-type virtual synchronous machine obtained in Step 1. e The reactive power reference instruction Q of the network-type virtual synchronous machine ref Primary voltage regulation coefficient k q The voltage reference command E0 is used to obtain the dq axis output voltage reference command E of the network-type virtual synchronous machine through a voltage regulation control equation. d E q ;

[0013] Step 3, Rotor Motion Equations: The active power reference command P of the grid-type virtual synchronous machine is used. refSubtract the grid-connected active power P of the network-type virtual synchronous machine obtained in step 1. e The power difference ΔP is obtained. The power difference ΔP, the virtual inertia parameter J, the rated angular frequency ω0 and the virtual damping parameter D of the network-type virtual synchronous machine are used to obtain the angular frequency deviation Δω of the network-type virtual synchronous machine through the rotor motion equation.

[0014] Step 4: Based on the output phase angle generation part of the lead-lag compensation, the angular frequency deviation Δω of the network-type virtual synchronizer obtained in Step 3 is added to the rated angular frequency ω0 to obtain the output angular frequency ω of the network-type virtual synchronizer. The output angular frequency ω is then passed through the lead-lag compensation stage containing the lead compensation parameter T1 and the lag compensation parameter T2, and then through the integration operation stage to obtain the output phase angle θ of the network-type virtual synchronizer.

[0015] Step 5: First, based on the output phase angle θ of the network-type virtual synchronizer obtained in Step 4, and the reference command E for the dq-axis output voltage of the network-type virtual synchronizer obtained in Step 2. d E q The three-phase bridge arm voltage modulation signal E is obtained through single synchronous rotating coordinate inverse transformation. a E b E c The three-phase bridge arm voltage modulation signal E a E b E c The drive signals for the inverter bridge switching transistors of the network-type virtual synchronous machine are generated through the SVPWM modulation stage.

[0016] Preferably, the grid-connected active power P in step 1 e The calculation equation used is:

[0017] P e =1.5(U d I d +U q I q ),

[0018] Grid-connected reactive power Q e The calculation equation used is:

[0019] Q e =1.5(U q I d -U d I q ).

[0020] Preferably, the output voltage reference command E in step 2 d The calculation equation used is:

[0021] E d =E0+(Q ref -Qe )k q ,

[0022] Output voltage reference command E q The calculation equation used is:

[0023] E q =0.

[0024] Preferably, the equation used to calculate the angular frequency deviation Δω in step 3 is:

[0025]

[0026] In the formula, s is the Laplace operator.

[0027] Preferably, the equation used to calculate the output angular frequency ω in step 4 is:

[0028] ω = Δω + ω0,

[0029] The equation used to calculate the output phase angle θ is:

[0030]

[0031] In the formula, s is the Laplace operator.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] This invention discloses a control method for a grid-connected virtual synchronous machine based on lead-lag compensation. This method replaces the output phase angle generation stage of the grid-connected virtual synchronous machine control method with an output phase angle generation stage based on lead-lag compensation. By adjusting the additional lead and lag compensation parameters, it effectively solves the dynamic oscillation and overshoot problems of the grid-connected active power and output frequency of the grid-connected virtual synchronous machine under disturbances such as active power reference commands and grid frequency. Compared to the grid-connected virtual synchronous machine, it has advantages such as eliminating grid-connected active power steady-state deviation, more control degrees of freedom, faster grid-connected active power response speed, smaller output frequency response overshoot amplitude, and smaller output frequency change rate. It is applicable to the field of grid-connected control of grid-connected virtual synchronous machines in power electronics technology, as well as the field of microgrid integration into distribution networks that includes such grid-connected virtual synchronous machines. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the control principle of the network-type virtual synchronous machine according to an embodiment of the present invention.

[0035] Figure 2This is a calculation diagram of the output phase angle generation stage based on lead-lag correction.

[0036] Figure 3 This is an equivalent control structure diagram of the grid-connected active power closed loop of a network-type virtual synchronous machine according to an embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of coordinate transformation and modulation according to an embodiment of the present invention.

[0038] Figure 5 The comparison Bode plots before and after the application of this invention to the network-type virtual synchronizer are shown.

[0039] Figure 6 This is a comparison of the simulation waveforms of the network-type virtual synchronizer before and after applying this invention.

[0040] Figure 7 This is a comparison of experimental waveforms before and after the application of this invention to a network-type virtual synchronizer. Detailed Implementation

[0041] The following detailed embodiments will be further described in conjunction with the above-mentioned figures, as follows:

[0042] Please see Figure 1 The present invention proposes a network-type virtual synchronous machine control method based on lead-lag compensation, comprising the following steps:

[0043] Step 1, power calculation section: First, collect the grid-connected current i of the grid-connected virtual synchronous machine. a i b i c and output voltage u a u b u c The dq component I of the grid-connected current oriented by the output phase angle θ of the network-type virtual synchronous machine is obtained through single synchronous rotating coordinate transformation. d I q and the dq component of the output voltage U d U q Then, the grid-connected active power P of the grid-type virtual synchronous machine is obtained through the power calculation equation. e And grid-connected reactive power Q e ;

[0044] That is, the active power P connected to the grid e The calculation equation used is:

[0045] P e =1.5(U d I d +U q I q ),

[0046] Grid-connected reactive power Qe The calculation equation used is:

[0047] Q e =1.5(U q I d -Ud Iq ).

[0048] Step 2, primary voltage regulation section, based on the grid-connected reactive power Q of the network-type virtual synchronous machine obtained in Step 1. e The reactive power reference instruction Q of the network-type virtual synchronous machine ref Primary voltage regulation coefficient k q The voltage reference command E0 is used to obtain the dq axis output voltage reference command E of the network-type virtual synchronous machine through a voltage regulation control equation. d E q ;

[0049] That is, the output voltage reference command E d The calculation equation used is:

[0050] E d =E0+(Q ref -Q e )k q ,

[0051] Output voltage reference command E q The calculation equation used is:

[0052] E q =0.

[0053] Step 3, Rotor Motion Equations: The active power reference command P of the grid-type virtual synchronous machine is used. ref Subtract the grid-connected active power P of the network-type virtual synchronous machine obtained in step 1. e The power difference ΔP is obtained. The power difference ΔP, the virtual inertia parameter J, the rated angular frequency ω0 and the virtual damping parameter D of the network-type virtual synchronous machine are used to obtain the angular frequency deviation Δω of the network-type virtual synchronous machine through the rotor motion equation.

[0054] That is, the equation used to calculate the angular frequency deviation Δω is:

[0055]

[0056] In the formula, s is the Laplace operator.

[0057] Step 4, the output phase angle generation part based on lead-lag correction, such as Figure 2As shown, the angular frequency deviation Δω of the network-type virtual synchronizer obtained in step 3 is added to the rated angular frequency ω0 to obtain the output angular frequency ω of the network-type virtual synchronizer. The output angular frequency ω is then passed through a lead-lag correction stage containing lead correction parameter T1 and lag correction parameter T2, and then through an integration operation stage to obtain the output phase angle θ of the network-type virtual synchronizer.

[0058] That is, the equation used to calculate the output angular frequency ω is:

[0059] ω = Δω + ω0,

[0060] The equation used to calculate the output phase angle θ is:

[0061]

[0062] In the formula, s is the Laplace operator.

[0063] according to Figure 1 The given grid-connected control structure, combined with the above calculation equations, can yield the following results: Figure 3 The diagram shows the equivalent control structure of the grid-connected virtual synchronous machine's active power closed loop. Figure 3 In the diagram, K is the synchronization voltage coefficient of the network-type virtual synchronous machine; δ is the power factor angle of the network-type virtual synchronous machine.

[0064] That is, the equation used to calculate the synchronization voltage coefficient K is:

[0065]

[0066] The equation used to calculate the power factor angle δ is:

[0067]

[0068] In the formula, U g is the grid voltage amplitude; E is the output voltage amplitude of the grid-type virtual synchronous machine; X is the equivalent inductive reactance of the grid line; ω g ω is the grid angular frequency; s is the Laplace operator.

[0069] Step 5, as follows Figure 4 As shown, first, based on the output phase angle θ of the network-type virtual synchronizer obtained in step 4, and the reference command E for the dq-axis output voltage of the network-type virtual synchronizer obtained in step 2... d E q The three-phase bridge arm voltage modulation signal E is obtained through single synchronous rotating coordinate inverse transformation. a E b E c The three-phase bridge arm voltage modulation signal E a E b E cThe drive signals for the inverter bridge switching transistors of the network-type virtual synchronous machine are generated through the SVPWM modulation stage.

[0070] Example

[0071] To verify the control effect of the proposed control method for a grid-connected virtual synchronous machine based on lead-lag compensation, the proposed control method was compared with existing grid-connected virtual synchronous machine (LLC-GFVSG) control methods and existing grid-connected virtual synchronous machine (IVD-GFVSG) control methods with increased virtual damping parameters (the latter two are mentioned in the background section as "Active Power Oscillation Suppression Strategy for Energy Storage VSG Grid Connection Based on Active Power Feedforward Compensation," Vol. 51, No. 14, pp. 118-126, *Power System Protection and Control*, 2023). The main comparison focused on their performance in responding to the active power reference command P. ref and grid frequency f g Grid-connected active power P under step disturbance conditions e And the dynamic response performance at the output frequency f. Specifically:

[0072] First, the relevant parameters are set. In this embodiment, the relevant parameters in the network-type virtual synchronous machine control method based on lead-lag compensation of the present invention are set as follows:

[0073] The rated capacity of the network-type virtual synchronous machine is 100kVA, and the active power reference command P... ref It has a power rating of 20 kW, a rated angular frequency ω0 of 314.16 rad / s, and a virtual inertia parameter J of 6 kg·m. 2 The virtual damping parameter D is 50.66 J / rad, and the primary voltage regulation coefficient k q 1.4×10 -4 V / var, grid voltage amplitude U g The output voltage amplitude E of the grid-type virtual synchronous machine is 311V, the equivalent inductive reactance X of the power grid line is 0.1Ω, and the synchronization voltage coefficient K = 1.5U. g E / X is 1450815. It is worth noting that if the virtual damping parameter D in the GFVSG is set to 253.3 J / rad, then the GFVSG will be equivalent to an IVD-GFVSG, indicating that the IVD-GFVSG is merely a special case of the GFVSG; similarly, if the lead compensation parameter T1 = 0 and the lag compensation parameter T2 = 0 in the LLC-GFVSG, then the LLC-GFVSG will be equivalent to a GFVSG, again indicating that the GFVSG is merely a special case of the LLC-GFVSG. Meanwhile, combined with... Figure 3Through a series of formula derivations, the active power reference command P of the GFVSG grid-connected system at this time can be obtained. ref To grid-connected active power P e The closed-loop transfer function is The damping ratio of the corresponding GFVSG grid-connected active power closed-loop control system That is, the GFVSG grid-connected active power closed-loop control system is an underdamped system, therefore the GFVSG grid-connected active power P e With output frequency f in active reference command P ref and grid frequency f g Under step disturbance conditions, dynamic oscillations and overshoot will inevitably occur. Furthermore, according to... Figure 3 Through a series of formula derivations, the active power reference command P of the IVD-GFVSG grid-connected system can be obtained. ref To grid-connected active power P e The closed-loop transfer function is The virtual damping parameter in G1(s) is set to D = 253.3 J / rad to ensure that IVD-GFVSG can suppress the grid-connected active power P of GFVSG to a certain extent. e With output frequency f in active reference command P ref and grid frequency f g Dynamic oscillations and overshoot under step disturbances.

[0074] In this embodiment, the values ​​of the lead compensation parameter T1 and the lag compensation parameter T2 will be optimized to further optimize the grid-connected active power P of the LLC-GFVSG. e With output frequency f in active reference command P ref and grid frequency f g Dynamic response performance under a step disturbance. Similarly, according to Figure 3 Through a series of formula derivations, the active power reference command P of the LLC-GFVSG grid-connected system can be obtained. ref To grid-connected active power P e The closed-loop transfer function is Therefore, the grid-connected active power dynamic response performance of GFVSG, IVD-GFVSG, and LLC-GFVSG can be directly compared and analyzed using the closed-loop transfer functions G(s), G1(s), and G2(s). To further simplify the theoretical analysis process, the virtual damping parameter in LLC-GFVSG is set to D = 50.66 J / rad, and the lead compensation parameter and lag compensation parameter are set to T1 = 0.12 and T2 = 0.0007, respectively. Substituting the above parameters into the closed-loop transfer functions G2(s), G1(s), and G(s), respectively, the active power reference command step disturbance ΔP of the grid-connected active power closed-loop control system of LLC-GFVSG, IVD-GFVSG, and GFVSG can be obtained.ref To the grid-connected active power response ΔP e (ΔP e / ΔP ref For a comparison of the Bode plot, see [link / reference]. Figure 5 (a). Similarly, the grid angular frequency step disturbance Δω of the grid-connected active power closed-loop control system of LLC-GFVSG, IVD-GFVSG and GGFVSG can be obtained respectively. g To the grid-connected active power response ΔP e (ΔP e / Δω g Active reference command step disturbance ΔP ref Output angular frequency response Δω(Δω / ΔP) ref ) and the step disturbance of the power grid angular frequency Δω g Output angular frequency response Δω(Δω / Δω) g For comparison with the Bode plot, please refer to the details below. Figure 5 (b) Figure 5 (c) and Figure 5 (d). Among them, Figure 5 In this paper, GFVSG represents the Bode plot of an existing network-type virtual synchronizer control method, IVD-GFVSG represents the Bode plot of an existing network-type virtual synchronizer control method with increased virtual damping parameters, and LLC-GFVSG represents the Bode plot of a network-type virtual synchronizer control method based on lead-lag compensation proposed in this invention. Specifically, the curve pointed to by GFVSG is the Bode plot before the application of this invention, specifically the Bode plot using an existing network-type virtual synchronizer control method; the curve pointed to by IVD-GFVSG is the Bode plot before the application of this invention, specifically the Bode plot using an existing network-type virtual synchronizer control method with increased virtual damping parameters; and the curve pointed to by LLC-GFVSG is the Bode plot after the application of this invention, specifically the Bode plot using the network-type virtual synchronizer control method based on lead-lag compensation proposed in this invention.

[0075] according to Figure 5 It can be observed that, firstly, the ΔP of the GFVSG grid-connected active power closed-loop control system... e / ΔP ref ΔP e / Δω g , Δω / ΔP ref , Δω / Δω g The presence of resonance peaks before the cutoff frequency indicates that the grid-connected active power P of the GFVSG is... e With the output angular frequency ω in the active reference command P ref and the angular frequency ω of the power grid gDynamic oscillations and overshoot exist under step disturbance conditions; secondly, the ΔP of the LLC-GFVSG grid-connected active power closed-loop control system proposed in this invention... e / ΔP ref ΔP e / Δω g , Δω / ΔP ref , Δω / Δω g The absence of a significant resonance peak before the cutoff frequency indicates that the grid-connected active power P of the LLC-GFVSG is... e With the output angular frequency ω in the active reference command P ref and the angular frequency ω of the power grid g No dynamic oscillation problem exists under step disturbance conditions; III. ΔP of the LLC-GFVSG grid-connected active power closed-loop control system e / ΔP ref ΔP e / Δω g , Δω / ΔP ref , Δω / Δω g Compared to IVD-GFVSG, both exhibit smaller resonance peaks. This phenomenon indicates that the grid-connected active power closed-loop control system corresponding to LLC-GFVSG has a smaller resonance peak in the active power reference command P. ref and the angular frequency ω of the power grid g Under step disturbance conditions, the LLC-GFVSG exhibits smaller grid-connected active power overshoot and lower output frequency response overshoot, thus demonstrating better dynamic response performance. It is worth noting that the LLC-GFVSG also offers more adjustable parameters / control degrees of freedom and more flexible parameter selection. For example, by selecting appropriate values ​​for the lead compensation parameter T1 and the lag compensation parameter T2, the grid-connected active power P of the LLC-GFVSG can be flexibly optimized. e The dynamic response performance with respect to the output angular frequency ω will not be listed in detail due to space limitations.

[0076] Based on the above parameter settings, simulation and experimental comparison tests were conducted, as follows:

[0077] The simulation and experimental test conditions were set as follows: at the initial moment, the grid-type virtual synchronous machine stably outputs 20kW of grid-connected active power, and the grid frequency f g Maintaining a constant 50Hz, the active power reference command P is available at 4.0s. ref The power output jumps from 20kW to 60kW, while the grid frequency f changes at 7.0s. g The frequency drops from 50Hz to 49.95Hz in a step.

[0078] Based on the above working conditions, the following results were obtained: Figure 6 and Figure 7 The simulation and experimental test comparison chart shown below, in which, Figure 6 and Figure 7 In this invention, LLC-GFVSG represents a network-type virtual synchronous machine control method based on lead-lag compensation, IVD-GFVSG represents an existing network-type virtual synchronous machine control method with increased virtual damping parameters, and GFVSG represents an existing network-type virtual synchronous machine control method. Specifically, the curve pointed to by LLC-GFVSG is the dynamic response test waveform after applying this invention, specifically the dynamic response test waveform of the proposed network-type virtual synchronous machine control method based on lead-lag compensation; the curve pointed to by IVD-GFVSG is the dynamic response test waveform before applying this invention, specifically the dynamic response test waveform of the existing network-type virtual synchronous machine control method with increased virtual damping parameters; and the curve pointed to by GFVSG is the dynamic response test waveform before applying this invention, specifically the dynamic response test waveform of the existing network-type virtual synchronous machine control method.

[0079] according to Figure 6 (a) It can be seen that: 1. The grid-connected active power and output frequency corresponding to the LLC-GFVSG proposed in this invention have no dynamic oscillations or overshoots, while the grid-connected active power and output frequency corresponding to the existing GFVSG have large dynamic oscillations and overshoots, and the grid-connected active power corresponding to the existing IVD-GFVSG has dynamic oscillations and power overshoots, and the output frequency has dynamic oscillations; 2. The adjustment time of the grid-connected active power corresponding to the LLC-GFVSG proposed in this invention is 0.03s, which is less than the 0.313s corresponding to the existing IVD-GFVSG and 0.75s corresponding to the GFVSG; 3. The output frequency response overshoot amplitude of the LLC-GFVSG proposed in this invention is 0.03Hz, which is less than the 0.1Hz corresponding to the existing IVD-GFVSG and 0.05Hz corresponding to the GFVSG. Therefore, it can be concluded that the LLC-GFVSG proposed in this invention, compared to the existing IVD-GFVSG and the existing GFVSG, has better performance in terms of active power reference command P. ref During the jump from 20kW to 60kW, the grid-connected active power showed no oscillation or overshoot and had a faster response speed, with no output frequency oscillation and a smaller frequency response overshoot.

[0080] And according to Figure 6(b) It can be seen that: 1. The grid-connected active power and output frequency corresponding to the LLC-GFVSG proposed in this invention do not exhibit dynamic oscillations or overshoot, while the grid-connected active power and output frequency corresponding to the existing GFVSG exhibit significant dynamic oscillations and overshoot. The grid-connected active power corresponding to the existing IVD-GFVSG exhibits dynamic oscillations, power overshoot, and a 20kW steady-state deviation, and the output frequency exhibits dynamic oscillations; 2. The adjustment time of the grid-connected active power corresponding to the LLC-GFVSG proposed in this invention is 0.01s, which is less than the 0.272s corresponding to the existing IVD-GFVSG and the 0.699s corresponding to the existing GFVSG; 3. The frequency change rate of the output frequency corresponding to the LLC-GFVSG proposed in this invention is 1.79 rad / s. 2 It is less than the 3.03 rad / s corresponding to the existing IVD-GFVSG. 2 The corresponding 4.93 rad / s of the existing GFVSG 2 Therefore, it can be seen that the LLC-GFVSG proposed in this invention, compared with existing IVD-GFVSG and existing GFVSG, has advantages in terms of grid frequency f. g During the process of stepping down from 50Hz to 49.95Hz, the grid-connected active power does not exhibit dynamic oscillation, power overshoot, or steady-state deviation, and has a faster response speed. The output frequency has no dynamic oscillation and a smaller frequency change rate.

[0081] according to Figure 7 (a) It can be seen that: 1. The grid-connected active power and output frequency corresponding to the LLC-GFVSG proposed in this invention have no dynamic oscillations or overshoots, while the grid-connected active power and output frequency corresponding to the existing GFVSG have large dynamic oscillations and overshoots, and the grid-connected active power corresponding to the existing IVD-GFVSG has dynamic oscillations and power overshoots, and the output frequency has dynamic oscillations; 2. The adjustment time of the grid-connected active power corresponding to the LLC-GFVSG proposed in this invention is 0.041s, which is less than the 0.362s corresponding to the existing IVD-GFVSG and the 0.791s corresponding to the existing GFVSG; 3. The output frequency response overshoot amplitude corresponding to the LLC-GFVSG proposed in this invention is 0.04Hz, which is less than the 0.06Hz corresponding to the existing IVD-GFVSG and the 0.09Hz corresponding to the existing GFVSG. Therefore, it can be concluded that the LLC-GFVSG proposed in this invention, compared to the existing IVD-GFVSG and the existing GFVSG, has better performance in terms of active power reference command P. ref During the jump from 20kW to 60kW, the grid-connected active power showed no dynamic oscillation or overshoot and had a faster response speed. The output frequency also showed no dynamic oscillation and had a smaller frequency response overshoot.

[0082] And according to Figure 7(b) It can be seen that: 1. The grid-connected active power and output frequency corresponding to the LLC-GFVSG proposed in this invention do not exhibit dynamic oscillations or overshoot, while the grid-connected active power and output frequency corresponding to the existing GFVSG exhibit significant dynamic oscillations and overshoot. The grid-connected active power corresponding to the existing IVD-GFVSG exhibits dynamic oscillations, power overshoot, and a 20kW steady-state deviation, and the output frequency exhibits dynamic oscillations; 2. The adjustment time of the grid-connected active power corresponding to the LLC-GFVSG proposed in this invention is 0.012s, which is less than the 0.355s corresponding to the existing IVD-GFVSG and the 0.75s corresponding to the existing GFVSG; 3. The frequency change rate of the output frequency corresponding to the LLC-GFVSG proposed in this invention is 2.15 rad / s. 2 It is less than the existing IVD-GFVSG corresponding to 3.63 rad / s 2 The corresponding 5.62 rad / s of the existing GFVSG 2 Therefore, it can be seen that the LLC-GFVSG proposed in this invention, compared with existing IVD-GFVSG and existing GFVSG, has advantages in terms of grid frequency f. g During the process of stepping down from 50Hz to 49.95Hz, the grid-connected active power does not exhibit dynamic oscillation, power overshoot, or steady-state deviation, and has a faster response speed. The output frequency has no dynamic oscillation and a smaller frequency change rate.

[0083] Will Figure 7 (a) and Figure 6 Comparing the results of (a), it is not difficult to see that this implementation method Figure 7 The experimental test results in (a) can be compared with those in (a) Figure 6 The simulation test results in (a) maintain a one-to-one correspondence, both of which fully demonstrate that, on the one hand, the LLC-GFVSG proposed in this invention can solve the grid-connected active power P problem of existing GFVSG and existing IVD-GFVSG. e With output frequency f in active reference command P ref The present invention addresses the issues of dynamic oscillation and overshoot that easily occur under step disturbances. Furthermore, compared to existing GFVSGs and IVD-GFVSGs, the LLC-GFVSG proposed in this invention exhibits advantages such as smaller output frequency response overshoot amplitude and faster grid-connected active power dynamic response speed under active power reference command (Pref) step disturbances. Therefore, the LLC-GFVSG proposed in this invention provides better control performance compared to existing GFVSGs and IVD-GFVSGs.

[0084] And again Figure 7 (b) and Figure 6 (b) Comparing the results, it is not difficult to see that this implementation method Figure 7 The experimental test results in (b) can be compared with those in [the other two] Figure 6(b) The simulation test comparison results maintain a one-to-one correspondence, both of which fully demonstrate that, on the one hand, the LLC-GFVSG proposed in this invention can solve the grid-connected active power P problem of existing GFVSG and existing IVD-GFVSG. e With output frequency f at grid frequency f g Dynamic oscillations and overshoot problems are prone to occur under step disturbances; on the other hand, the LLC-GFVSG proposed in this invention, compared with existing GFVSG and existing IVD-GFVSG, has a lower power grid frequency f g Under step disturbances, it has the advantages of no grid-connected active power overshoot, no output frequency response overshoot amplitude, and a smaller output frequency change rate. Therefore, compared with existing GFVSG and existing IVD-GFVSG, the LLC-GFVSG proposed in this invention has better control performance.

[0085] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A control method for a network-type virtual synchronous machine based on lead-lag compensation, characterized in that, Includes the following steps: Step 1, power calculation section: First, collect the grid-connected current i of the grid-connected virtual synchronous machine. a i b i c and output voltage u a u b u c The dq component I of the grid-connected current oriented by the output phase angle θ of the network-type virtual synchronous machine is obtained through single synchronous rotating coordinate transformation. d I q and the dq component of the output voltage U d U q Then, the grid-connected active power P of the grid-type virtual synchronous machine is obtained through the power calculation equation. e And grid-connected reactive power Q e ; Step 2, primary voltage regulation section, based on the grid-connected reactive power Qe of the grid-type virtual synchronous machine obtained in Step 1 and the reactive power reference command Q of the grid-type virtual synchronous machine. ref Primary voltage regulation coefficient k q The voltage reference command E0 is used to obtain the dq axis output voltage reference command E of the network-type virtual synchronous machine through a voltage regulation control equation. d E q ; Step 3, Rotor Motion Equations: The active power reference command P of the grid-type virtual synchronous machine is used. ref Subtract the grid-connected active power P of the network-type virtual synchronous machine obtained in step 1. e The power difference ΔP is obtained. The power difference ΔP, the virtual inertia parameter J, the rated angular frequency ω0 and the virtual damping parameter D of the network-type virtual synchronous machine are used to obtain the angular frequency deviation Δω of the network-type virtual synchronous machine through the rotor motion equation. Step 4: Based on the output phase angle generation part of the lead-lag compensation, the angular frequency deviation Δω of the network-type virtual synchronizer obtained in Step 3 is added to the rated angular frequency ω0 to obtain the output angular frequency ω of the network-type virtual synchronizer. The output angular frequency ω is then passed through the lead-lag compensation stage containing the lead compensation parameter T1 and the lag compensation parameter T2, and then through the integration operation stage to obtain the output phase angle θ of the network-type virtual synchronizer. Step 5: First, based on the output phase angle θ of the network-type virtual synchronizer obtained in Step 4, and the reference command E for the dq-axis output voltage of the network-type virtual synchronizer obtained in Step 2. d E q The three-phase bridge arm voltage modulation signal E is obtained through single synchronous rotating coordinate inverse transformation. a E b E c The three-phase bridge arm voltage modulation signal E a E b E c The drive signals for the inverter bridge switching transistors of the network-type virtual synchronous machine are generated through the SVPWM modulation stage.

2. The control method for a network-type virtual synchronous machine based on lead-lag compensation according to claim 1, characterized in that, The grid-connected active power P in step 1 e The calculation equation used is: P e =1.5(U d AND d +U q AND q ), Grid-connected reactive power Q e The calculation formula used is: Q e =1.5(U q I d -U d I q )。 3. The control method for a network-type virtual synchronous machine based on lead-lag compensation according to claim 1, characterized in that, Output voltage reference command E in step 2 d The calculation equation used is: E d =(Q ref -Q e )k q +E0, Output voltage reference command E q The calculation equation used is: E q ＝0。 4. The control method for a network-type virtual synchronous machine based on lead-lag compensation according to claim 1, characterized in that, The equation used to calculate the angular frequency deviation Δω in step 3 is: In the formula, s is the Laplace operator.

5. The control method for a network-type virtual synchronous machine based on lead-lag compensation according to claim 1, characterized in that, The equation used to calculate the output angular frequency ω in step 4 is: ω = Δω + ω0, The equation used to calculate the output phase angle θ is: In the formula, s is the Laplace operator.

Images